Pity the entre­pren­eur who wants to do busi­ness under such con­di­tions. If goods travel at 75 miles a day [â€¦] it is almost impossible to import mater­i­als or export products prof­it­ably from Africa’s back­wa­ters. The eco­nom­ic geo­graph­ers Nuno LimÃ£o and Tony Ven­ables have estim­ated that high trans­port costs explain almost all of Africa’s eco­nom­ic isol­a­tion. Cer­tainly, export­ers have not been able to take full advant­age of US and EU trade con­ces­sions.